app_odoo_customize/views/app_odoo_customize_view.xml
<?xml version="1.0" encoding="UTF-8"?>
<odoo>
<data>
<template id="switch_language" name="switch_language assets" inherit_id="web.assets_backend">
<xpath expr="." position="inside">
<link rel="stylesheet" href="/app_odoo_customize/static/src/css/app.css"/>
<script type="text/javascript" src="/app_odoo_customize/static/src/js/switch_language.js"></script>
<script type="text/javascript" src="/app_odoo_customize/static/src/js/customize_user_menu.js"></script>
<script type="text/javascript" src="/app_odoo_customize/static/src/js/app_window_title.js"/>
</xpath>
</template>
</data>
</odoo>